Archive for December, 2009

Wind turbines, energy-efficient light bulbs, and hybrid cars and three of the most iconic products in the lineup of green technologies that can help us build a cleaner world. But in an ironic twist, these technologies all rely on elements called rare earths, which are primarily extracted from environmentally destructive mines in China.

The environmental damage can be seen in the red-brown scars of barren clay that run down narrow valleys and the dead lands below, where emerald rice fields once grew. Miners scrape off the topsoil and shovel golden-flecked clay into dirt pits, using acids to extract the rare earths. The acids ultimately wash into streams and rivers, destroying rice paddies and fish farms and tainting water supplies [The New York Times].

The newest big thing in solar power is a set of solar panels so small that they could be mistaken for specks of glitter.

Researchers at Sandia National Laboratories have produced “microcells” that are thinner than a human hair, which are made from crystalline silicon and use 100 times less material to generate the same amount of electricity as standard solar cells made from 6-inch square solar wafers [Inhabitat].

What’s more, the tiny solar cells could be attached to flexible materials like plastic or cloth, letting inventors dream of a solar power tie that could recharge your cell phone, or a tent that could run electric lights at night.

A fossil dwarf whale, first discovered in Australia over 70 years ago, had an unusual feeding habit. The whale sucked up mud pies in order to feast on sea bed critters, according to a new study. The fossil whale, thought to be between 25 and 28 million years old, hints that mud sucking might have been a precursor to the filter feeding used by today’s baleen whales [National Geographic News]. Modern filter feeders use what’s called baleen—tiny hair-like structures—to filter their prey from the seawater. The most famous, and the largest, baleen species is the blue whale, and the ancient dwarf whale may be a distant relative, say the researchers.

Oddly, the dwarf whale also had teeth, which the researchers speculate were used to chomp on bulky prey that their tongue and facial muscles slurped off the sea floor. Modern whales with baleen plates eat tiny prey such as krill and are distinct from toothed whales, which include beaked whales and orcas (aka killer whales). The ancient whale, Mammalodon colliveri, had a total body length of about 3m. But it appears to have been a bizarre evolutionary “splinter group” from the evolutionary lineage which later led to the 30m-long blue whale [BBC News]. Researchers say the dwarf whale most likely evolved from much larger ancestors and adds evidence to the theory that proto-baleen whales diversified into many experimental body forms, say the researchers, who published their work in the Zoological Journal of the Linnean Society.

Chalk up another unexpected consequence of pumping too much carbon dioxide into the air: According to a new study, the excess CO2 that ends up in seawater is gradually making the oceans noisier.

The changing chemistry of the ocean is one of the major impacts of CO2 emissions. The dissolved gas is changing the pH of the water by making it more acidic, which makes life harder for corals and marine critters with calcium carbonate shells that are corroded by the acidic water. But the new study, published in Nature Geoscience, found that changing the pH of the oceans also reduces the levels of chemicals that absorb sound, like magnesium sulphate and boric acid.

Low-frequency sound in the ocean is produced by natural phenomena such as rain, waves and marine life, and by human activities such as sonar systems, shipping and construction. The sound is absorbed mainly through the viscosity of the water and the presence of certain dissolved chemicals…. But the concentration of chemicals that absorb sound in the oceans has declined as a result of ocean acidification [AFP]. The study found that sound absorption could fall by some 60 percent in high latitudes and deep waters by 2100.

Millions of years ago, a koala looked more like a possum. By studying rare skulls of the famous marsupial that date between 5 and 24 million years old, a team of Australian researchers propose how it got to looking like it does today, with findings published in the Journal of Vertebrate Paleontology.

Food was one driver, they say—millions of years ago koalas ate a variety of foods. The dietary switch to an exclusive eucalypt diet seems to have occurred during the late Miocene period, some 12 to five million years ago, when a drying climate made eucalyptus the dominant forest species [Canberra Times]. As a result, they lost their snouts and developed powerful jaw muscles.

When it comes to understanding fire, chimpanzees might have a leg up not only on the rest of the animal kingdom, but also on those of us in the human species who would sprint in the other direction at the sight of a blaze. A study published in the American Journal of Physical Anthropology argues that these primates don’t panic when the flames start, and could even understand the basics about how fire behaves.

Primatologist Jill Pruetz has been observing chimps in Senegal since 2001, but it was in 2006 that she first noticed how the animals reacted to wildfire. When people in the area set fires to clear the land, the chimps refused to tuck tail and run. “It was the end of the dry season, so the fires burn so hot and burn up trees really fast, and they were so calm about it,” Pruetz said of the chimps. “They were a lot better than I was, that’s for sure” [LiveScience].

Friday night, after a two-week diplomacy fest that could be called “difficult” at best, leaders of some of the most powerful countries in the world announced that they reached an 11th hour agreement to conclude the United Nations Copenhagen climate summit. After speaking to the assembly, President Barack Obama spent the day going in and out of meetings with Chinese prime minister Wen Jiabao. They met later with Mammoghan Singh of India, President Luiz Inácio Lula da Silva of Brazil, and South African President Jacob Zuma, before a White House official leaked that these big players had reached an agreement.

Researchers from the Imperial College London have a new strategy to combat malaria. The species of mosquito responsible for the spread of malaria in Africa, Anopheles gambiae, only mates once during its life. Putting a stop to their one shot at reproduction should slow down malaria transmission. Anopheles males deploy a glob of proteins and fluids known as a “mating plug” that is essential for ensuring sperm is correctly retained in the female’s sperm storage organ, from where she can fertilise eggs over the course of her lifetime [BBC News]. Without a mating plug, the sperm is not stored and the mosquitoes can’t reproduce.Simply put, the researchers want to prevent male mosquitoes from plugging in the wild.

Anopheles gambiae is the only known species of mosquito to use a mating plug. (However, mating plugs are found in other animals where they prevent multiple males from reproducing with a female. Plug checking mice in research laboratories is a right of passage for many graduate students.) In their research, written up in the journal PLoS Biology, scientists were able to alter the mosquitoes’ genes so that they could no longer form a plug, and thus were unable to reproduce. If this process could be developed for use in the field, perhaps in a spray form like an insecticide, it could “effectively induce sterility in female mosquitoes in the wild,” [study author Flaminia] Catteruccia wrote, offering potential as “one more weapon in the arsenal against malaria” [Reuters]. The WHO is optimistic that their increased funding efforts will produce more technologies similar to this one and that, hopefully, one of them will prove effective.

Earlier this month DISCOVER covered the 213-million-year-old fossils of the theropod Tawa hallae, a dinosaur ancestor that could show how early dinos spread around the world. Now, in a study (in press) in the Proceedings of the National Academy of Sciences, another research team has uncovered a surprise in the bones of a theropod from almost 100 million years later. By that time, these creatures may have adopted a clever new weapon: venom.

Sinornithosaurus lived 125 million years ago in what’s now China, and while it might have been covered in feathers (and the size of a turkey), the researchers say it attacked like modern rear-fanged snakes. Rear-fanged snakes don’t inject venom. Instead, the toxin flows down a telltale groove in a fang’s surface and into the bite wound, inducing a state of shock [National Geographic].

Hot on the heels of the story of lab-built red blood cells that DISCOVER covered on Tuesday, a different team of scientists have announced another step forward. Bioengineer Erin Lavik announced that her team built synthetic platelets that, when given intravenously to rodents, could slow their bleeding after a cut. The study appears in Science Translational Medicine.

Your normal platelets exist in the bloodstream and use proteins to bind together and close off the bleeding when you get a cut. Lavik’s synthetic version is a nanoparticle that her team injected into the rodents intravenously. The synthetic platelets augment this process, bonding with natural blood platelets and acting as a nanostructure boosting the natural platelets’ ability to form a solid barrier that stops bleeding [Popular Science]. The rodents with synthetic platelets stopped bleeding 23 percent faster than those without.